RS Pro Passive Oscilloscope Probes - RS-LF Series. RS Pro Passive Oscilloscope Probe RS-LF Series. Ergonomically designed probe suitable for use with all major brands of oscilloscopes as well as our range. RS Pro passive oscilloscope probes don't require a power supply or batteries so are lightweight and easily portable. Contents. LF Oscilloscope Probe Protective caps Spring hook tip Spare probe tip Grounding lead terminated with insulated crocodile clip Trimmer tool. Probe Options. RS - LF 112 : RS stock no: ; 146-6612 146-6612. RS - LF 212 : RS stock no: ; 146-6613 146-6613. RS - LF 312 : RS stock no: ; 146-6614 146-6614. RS - LF 312-2-6 : RS stock no: ; 146-6615 146-6615 (2 pieces RS LF-312). Attenuation Ratio. 1:1 max. Input voltage 400 V CAT I (VDC + Peak AC) derating with frequency. 10:1 max. Input voltage 600 V CAT I (VDC + Peak AC) derating with frequency